Electrolytic capacitors (e.g., tantalum capacitors) are increasingly being used in the design of circuits due to their volumetric efficiency, reliability, and process compatibility. For example, one type of capacitor that has been developed is a solid electrolytic capacitor element that includes a tantalum anode, dielectric layer, and conductive polymer solid electrolyte. In order to surface mount the capacitor element, the anode is connected to an anode termination and the solid electrolyte is connected to a cathode termination. Further, to help protect the capacitor from the exterior environment and provide it with good mechanical stability, the capacitor element is also encapsulated with a resinous casing material (e.g., epoxy resin) so that a portion of the anode and cathode terminations remain exposed for mounting to a surface. Unfortunately, it has been discovered that high temperatures that are often used during manufacture of the capacitor (e.g., reflow) can cause micro-cracks to form in the anode and/or cathode terminations. When exposed to high humidity levels, these micro-cracks can absorb moisture, which can result in oxidation of the conductive polymer solid electrolyte and lead to a rapid deterioration of the electrical properties.
As such, a need exists for an improved solid electrolytic capacitor for use at high humidity levels.